I have it too...
I think this is what the OP is referring to... (not my pic)
Its not animal, it's either filamentous bacterial or fungal IMO.
It is only on the under side of live rock, in good glow areas, out of light.
It seemed to start after I tried bakers yeast or Dr Tim's waste away to fend off some horrible diatoms. (which didn't work)
It doesn't appear on all rocks, only but about 10% of them, over the past month it seems to be receding, I don't see any snails or hermits interested in it.
You can not syhpon it off, or wipe it off, but it does brush off with a tooth brush. Doesn't seem to do any harm but I do not brush it incase it spreads....
But I would love to know what it is so that I can get rid of it and stop it coming back.
In general, my water is very stable parameters of
temp 80 oF
1.026 SG
8.9 dkH
430 Ca
1300 Mg
0 NH3
8-10 NH4+
0.2 NO3
0.002 PO4
400 K
No algae in DT, just a couple of feather (non bryopsis) tuffs on 2 rocks I can't remove or safely get H2O2 too.
Refugium, spinning chaeto, dragons breathe. Marine pure 8x8x2 block.
GFO and GAC and skimmer.
Feed washed frozen mysis and cyclops only.
Dose Alk, Ca, Mg, NOPOX (when needed, this all started before dosing any carbon) and Red sea colors A B C D.
I have tried Korallen Zuch - cynoclean = no change
On googling, possible cures may be H2O2 or Dr Tims waste away.....
Any help really appreciated!!!
